A novel technology allowing to create a 3D "scaffold" to grow cells from the retina may pave the way for potential new treatments for a common cause of blindness.
Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, affecting nearly 20 million people in the United States. As the population ages, global AMD cases are expected to increase and reach 288 million by 2040.
Scientists from Anglia Ruskin University (ARU) developed a technology called "electrospinning," which can be used to create a 3D scaffold to grow retinal pigment epithelial (RPE) cells. These cells sit just outside the neural part of the retina and, when damaged, can cause vision to deteriorate.
In the trial, the findings of which were published in the journal Materials & Design, treating the scaffold with a steroid called fluocinolone acetonide, which protects against inflammation, resulted in increased resilience of the cells, promoting the growth of eye cells.
In these 3D scaffolds, cell growth and differentiation — the process of acquiring specialized structures and functions — were sustained for at least 60 days.
AMD can be caused by changes in Bruch's membrane, which supports the RPE cells, and the breakdown of the choriocapillaris, a dense capillary network adjacent to the other side of Bruch's membrane.
In Western populations, the most common cause of sight loss is an accumulation of lipid deposits called drusen and the subsequent degeneration of parts of the RPE, the choriocapillaris, and the outer retina.
"In the past, scientists would grow cells on a flat surface, which is not biologically relevant. Using these new techniques, the cell line has been shown to thrive in the 3D environment provided by the scaffolds," says lead author Professor Barbara Pierscionek, Deputy Dean at Anglia Ruskin University.
This newly-developed system could be used as a substitute for Bruch's membrane, providing synthetic, non-toxic, biostable support for transplantation of the RPE cells.
The researchers say their findings could revolutionize treatment for AMD and lead to the development of ocular tissue for transplantation into the patient's eye. However, electrospinning will have to first be tested in animals and clinical trials to be applied in human patients.
Although there is still no cure for blindness, scientists have succeeded in developing treatments for various forms of vision loss. In 2013, the U.S. Food and Drug Administration (FDA) approved bionic eyes, also known as visual prostheses, in patients with retinitis pigmentosa, a rare eye disease. However, it only restores the ability to see light or flashes of light.
Gene therapies also show promise in treating vision problems. For example, the FDA-approved Luxturna (voretigene neparvovec-rzyl) is used to improve sight in people with a specific form of retinal dystrophy caused by a mutation in the RPE65 gene. The treatment delivers a replacement of the mutated gene directly to retinal tissues.
Clinical trials are underway to treat AMD with stem cell therapy. Stem cells may be able to replace lost or damaged cells in the eye that are responsible for vision loss.
- Anglia Ruskin University. Retina cell breakthrough could help treat blindness.
- Materials & Design. Retinal pigment epithelial cells can be cultured on fluocinolone acetonide treated nanofibrous scaffold.
- The Lancet Global Health. Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis.
- FDA. FDA approves novel gene therapy to treat patients with a rare form of inherited vision loss.
- National Library of Medicine. A review and update on the current status of retinal prostheses (bionic eye).
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- Macular Society. Stem Cell Therapy.